From e5054c9aefd26ac2401f4b17eda82fab71796dca Mon Sep 17 00:00:00 2001 From: xuejiufei Date: Fri, 25 Mar 2016 14:21:38 -0700 Subject: [PATCH] ocfs2/dlm: move lock to the tail of grant queue while doing in-place convert We have found a bug when two nodes doing umount one after another. 1) Node 1 migrate a lockres that has 3 locks in grant queue such as N2(PR)<->N3(NL)<->N4(PR) to N2. After migration, lvb of the lock N3(NL) and N4(PR) are empty on node 2 because migration target do not copy lvb to these two lock. 2) Node 3 want to convert to PR, it can be granted in __dlmconvert_master(), and the order of these locks is unchanged. The lvb of the lock N3(PR) on node 2 is copyed from lockres in function dlm_update_lvb() while the lvb of lock N4(PR) is still empty. 3) Node 2 want to leave domain, it will migrate this lockres to node 3. Then node 2 will trigger the BUG in dlm_prepare_lvb_for_migration() when adding the lock N4(PR) to mres with the following message because the lvb of mres is already copied from lock N3(PR), but the lvb of lock N4(PR) is empty. "Mismatched lvb in lock cookie=%u:%llu, name=%.*s, node=%u" [akpm@linux-foundation.org: tweak comment] Signed-off-by: xuejiufei Acked-by: Joseph Qi Cc: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ocfs2/dlm/dlmconvert.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/ocfs2/dlm/dlmconvert.c b/fs/ocfs2/dlm/dlmconvert.c index f90931335c6b..cdeafb4e7ed6 100644 --- a/fs/ocfs2/dlm/dlmconvert.c +++ b/fs/ocfs2/dlm/dlmconvert.c @@ -212,6 +212,12 @@ grant: if (lock->lksb->flags & DLM_LKSB_PUT_LVB) memcpy(res->lvb, lock->lksb->lvb, DLM_LVB_LEN); + /* + * Move the lock to the tail because it may be the only lock which has + * an invalid lvb. + */ + list_move_tail(&lock->list, &res->granted); + status = DLM_NORMAL; *call_ast = 1; goto unlock_exit; -- 2.20.1